A three-step mechanism for the reaction of hydrogen peroxide with bromine in acidic solution is proposed.
I. Br2 + Br− ⇌ Br3− (fast equilibrium)
II. Br3− + H2O2 → 2 Br− + HOBr (slow)
III. HOBr + Br− + H+ → Br2 + H2O (fast)
Which species is most likely acting as a catalyst in this mechanism?
a) Br3−
b) Br2
c) Br−
d) HOBr